When I switch to command line I can log in, but I have no idea how to fix this issue there. Network is not working then either, although the computer is connected via cable. Maybe the network config is not loaded (DHCP is off). So I cannot run updates or reinstall.

I tried all options in recovery mode. Enable networking is not working.

3 Answers
3

I had the same problem. A google search indicates that many people seem to have this problem, and I don't see solutions. Startpar starts runlevel scripts in parallel, so is there to speed up the booting process. It is part of the sysvinit package, which is marked as essential. This means it is hard to remove or substitute, which was one of my first ideas.

I spent several hours extensively searching and trying to remove this problem in order to have my system boot again. I even downloaded and compiled the sysvinit repository, compiled it and replace my existing binary in /sbin/ with the built one (v0.58->v0.59), but I noticed that this svn repository was not very new. All this to no avail.

I ended up downgrading my system again by doing a reinstall from live-CD. (BTW, Precise is supported until 2017.)

(I don't have 10 reputation points to post more than two links, so I had to cut back.)

When I attempt to install and boot using lightdm, the system stops at startpar-bridge and will not advance into boot. I switched to kdm and system boots properly. This bug reared it's ugly head after installation of nvidia-331 from the Ubuntu repo's.

This into 14.04 Kubuntu.

I switched to gdm as a workaround, and now I can log in. See if that does it for you.